Exclusive: David Hagaman Discusses Applying WVU Baseball Lessons to Pro Ball

David Hagaman burst on the scene with WVU Baseball as a redshirt freshman, pitching to a 3.52 ERA with 40 strikeouts in 38.1 innings out of the bullpen during the 2023 campaign.

With most young pitchers expected to take their lumps, Hagaman’s hot start made him a breakout candidate heading into 2024. His strikeout rate increased — 49 punchouts in 35 innings — but his ERA surged as well. Hagaman’s season ended in mid-April and he underwent internal brace surgery, an operation similar to the dreaded Tommy John surgery, the following month.

His penchant for punchouts earned a fourth round pick (No. 133 overall) from the Texas Rangers, but Hagaman remained a raw prospect. He relied on two pitches during his time with the Mountaineers, a fastball and a slider, and knew he needed more than that in order to outduel professional hitters. Once healthy, the 6-foot-3 right-hander began tooling with a curveball, that third offering making a move to the starting rotation a legitimate possibility.

Hagaman went to the Arizona Diamondbacks at the trade deadline in 2025 as part of the package for Merrill Kelly, and debuted his curveball soon thereafter.

He spoke with West Virginia Sports Now recently in Hillsboro, Oregon while Hagaman is there with the Diamondbacks’ High-A affiliate.

“I was just coming back from Tommy John surgery and was working on adding a new pitch to the repertoire. Switching over to a starter, I figured give it a different look. So I started messing around with the curveball, talking to some of the guys with the Rangers’ org that threw curveballs and they gave me some good tips,” Hagaman said. “Just played catch with it. And then once I got over here with the D-Backs I figured it was time to see if I could throw it in a game. They gave me the green light, and just went from there.”

Refining His Game

Hagaman pitched to a 2.98 ERA in 2025, jumping from the Rangers’ rookie ball team to High-A. He struck out 55 batters and issued 10 walks in 42.1 innings and said, although he managed to fool batters consistently with pitches outside the zone, he wants to focus on staying ahead in the count this season, an approach that will help him as he climbs through the system and faces more polished pitchers.

“Just getting all the pitches in the zone a little bit more. Last year I relied big on chase,” Hagaman said. “So zoning in more and getting stuff more over the plate. Getting ahead of guys, staying ahead of guys and just attacking hitters.”

MLB Pipeline now ranks Hagaman as the No. 8 prospect in the Diamondbacks’ organization. He said he feels that professional baseball gives him the opportunity to really pitch, not just throw as hard as he can in order to catch the eye of scouts.

“Pro ball, it’s a good experience, it’s a lot of fun playing with these guys. I think it’s a different view in terms of how you work your whole life to get drafted and now you have a shot, so you can kind of worry about pitching and how you can attack hitters instead of just trying to light up the gun all the time,” Hagaman said. You can pull back from that and try to attack hitters a little bit better. So that’s the biggest difference I’ve noticed in my time here and I’m enjoying it so far.”

WVU Lessons

Even while trying to rear back and light up the radar gun, Hagaman said that his time at WVU taught him the importance of hitting his spots, a lesson he continues to apply as he fleshes out his repertoire.

“With only two options you really do have to execute your pitches. So it was a big focus on executing the fastball up in the zone, getting the slider down and away to a righty, really just sticking with that,” Hagaman said. “Staying over the plate and trying to attack them with everything. So it kind of helped show me ‘be aggressive with your pitches, don’t take anything off and go right at them.'”

The Mountaineers have turned into a pitching factory of sorts in recent seasons, turning players from the lower levels of the sport like Blaine Traxel, Derek Clark (D-II Northwood), Griffin Kirn (D-II Quincy) and Ian Korn (D-II IUP) into legitimate power conference options. Hagaman said that the Mountaineers’ success — and his own — stems from a simple coaching philosophy: throw strikes.

“The coaches do a phenomenal job of teaching their guys. You want to win ball games, you’ve got to throw the ball over the plate. You’ve got to go right after guys, walks lead to bad things,” Hagaman said. “I think they really hammer in the nail in terms of going after guys, giving them your best stuff and making them hit the ball. Also all the guys are usually always together and they’re always fighting for each other, always rooting for each other. So it’s nice to have that too.”

Professional Quality

Another weapon in the Mountaineers’ development toolbox is their state-of-the-art facility, opened in 2025 thanks to a donation from Diamondbacks’ majority owner Ken Kendrick, a West Virginia alumnus himself. While the facility opened after Hagaman’s time with WVU, he said he returned to Morgantown in the offseason to train there… and with experience in two professional organizations already, he has first-hand experience to articulate how it truly stacks up.  

Kelsie LeRose / WVSN

“I went back this past offseason, threw a lab there right before the fall league. So I use it and it’s a beautiful facility. I think they’re gonna have a lot of big things coming from there,” Hagaman said. “I think West Virginia is top of the line. I’ve been with two orgs now and been to both their labs, and I think West Virginia is up there if not better than both of the labs I’ve been in. So they do a phenomenal job with development, and I’m excited to see where the program goes.”

The Mountaineers began to foster ties with Kendrick in 2023, when they played a road series at Arizona. The Mountaineers stuck around in the Grand Canyon State for a Monday exhibition against the Diamondbacks and had a chance to tour their home stadium, Chase Field.

Hagaman said that WVU Baseball head coach Steve Sabins, then serving as an assistant, played a key role in building a relationship with Kendrick.

“We played U of A in 2023 very early in the season. Steve Sabins was working on getting a relationship with [Ken] Kendrick and so he introduced me to him in the dugout, we talked a little bit,” Hagaman said. “That was the first interaction we’ve had together, and then I’ve seen him at the complex a couple times.”